Rotary pumps and rotary motors



June 13, 1967 G. A. FAIRBAIRN ROTARY PUMPS AND ROTARY MOTORS 4 Sheets-Sheet 1 Filed June 30, 1966 l utor J1me 1967 :3. A. FAIRBAIRN 3,32

ROTARY PUMPS AND ROTARY MOTORS Filed June 30, 1966 4 Sheets-Sheet 2 (4 'IIlljff'l/Mfl/(IIIIIIIIIIIM/l;

l/flntor- George. Anthem FAIRBAIRN B, um, M wim L June 13, 1967 G. A. FAIRBAIRN 3,324I802 ROTARY PUMPS AND ROTARY MOTORS I Filed June 30, 1966 Sheets-$heet 3 Gum B3 MM. 4411 PM June 13, 1967 G. A. FAIRBAIRN 3,324,892

ROTARY PUMPS AND ROTARY MOTORS Filed June 30, 1966 4 Sheets-Sheet 4 Fig.4.

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United States Patent 3,324,802 ROTARY PUMPS AND ROTARY MQTDRS George Anthony Fairhairn, Green Gables, Mount Martha, Victoria, Australia Fiied June 30, 1966, Ser. No. 561,975 Claims priority, application Great Britain, Aug. 3, 1965, 33,947/ 65 13 Claims. (1. 103-125) This invention relates to rotary pumps for fluids as well as to fluid operated rotary motors, and which are of the positive displacement type.

The present application is a continuation-in-part of my former application Ser. No. 436,205, filed Mar 1, 1965, now abandoned.

Although the invention the subject of the present application is primarily applicable to rotary pumps for pumping liquids, as well as being applicable to rotary hydraulic motors, the invention in its broadest form is considered to be applicable to rotary pumps for pumping gases as Well as to pneumatically operated rotary motors.

In my earliest attempt to provide a rotary pump of the positive displacement type the pump comprised a casing having an annular chamber, the casing containing a rotor element provided with a single piston element traversing the annular chamber, a rotary valve element intersecting the annular chamber and arranged to rotate in timed relation with the rotation of the rotor element, said valve element being apertured to permit of the passage therethrough of the piston element, and an inlet and outiet port to the annular chamber positioned respectively on opposite sides of the intersection of the rotary valve element with the annular chamber, the arrangement being such that the piston element on advancing past the inlet port in a direction away from the adjacent valve element serves positively to force the fluid around the annular chamber to the outlet port from which it is discharged under pressure.

Thus in this prior proposal of myself, in operative relation to each rotary valve element and each inlet and outlet port disposed on opposite sides of said valve element at its position of intersection with the annular chamber, there was only a single piston element at any given time advancing the fluid around the annular chamber from the inlet port to the next successive outlet port in the direction of rotation of the rotor element.

Accordingly such prior proposal of myself, entailed the serious disadvantage that as soon as the piston element advanced past that edge of the outlet port which was rearmost in the direction of rotation of the rot-or element, such outlet port was connected through said annular chamber directly to the inlet port, such connection through said annular chamber being separate from and independent of said valve element intersection with the annular chamber.

Thus at this instant in the operation of the pump, there was necessarily a back flow of high pressure fluid from the delivery pipe of the outlet port, through the outlet port back along the annular chamber to the inlet port, which back flow of high pressure fluid continued until the piston element had by the rotation of the rotor element advanced past that edge of the inlet port referred to which was foremost in the direction of element rotation.

Such back flow of fluid not only seriously impaired the efliciency of the pump by interrupting the continuity of the pumping cycle to an extent such that for a substantial portion of each revolution of the rotor element no fluid was being delivered, but permitted the return to the inlet port of a substantial proportion of the high pressure fluid just delivered by the approaching of the piston element to the outlet port, the rear edge of which had just been uncovered by the advancing piston element, so as 3 ,324,802 Patented June 13, 1967 still further to reduce the pump efliciency. A similar loss of efliciency for each of the two reasons above explained would necessarily also occur in adapting my foregoing prior proposal, as a fluid operated rotary motor.

Also in non-public experiments conducted by myself in Australia with the prototype rotary water pump of the above prior proposal, the sudden reduction in outlet pressure which occurred consequential to the aforementioned back flow of the water around the annular chamber, produced most severe water hammer, which eifectively precluded any attempt to develop the pump commercially.

One of the objects of the present invention is to provide a rotary pump and a rotary motor of a particularly high efl'lciency.

A fiurther object of the present invention is to provide a rotary pump of the positive displacement type for pumping water in which water hammer is substantially eliminated.

The present invention is accordingly a rotary pump or motor comprising a casing having an annular chamber, the casing containing a rotor element provided'with a plurality of piston elements traversing the annular chamber, and spaced circumferentially therearound, one or more rotary valve elements of disc-like form intersecting the annular chamber, arranged to rotate in timed relation with the rotation of the rotor element, each valve element being arranged to rotate in one direction only for a given direction of rotation of the rotor element, each valve element being apertured to permit of the passage therethrough of each piston element with the plane of rotation of the disc-like valve element being transverse to the direction of passage therethrough of each piston element, an inlet and outlet port to the annular chamber positioned respectively on opposite sides of the position of intersection of each rotary valve element with the annular chamber, each outlet port being disposed immediately adjacent to the position of intersection of the corresponding rotary valve element with the annular chamber, the number of piston elements being greater than the total number of inlet ports and greater than the total number of outlet ports, the arrangement being such that at the instant that a piston element commences to uncover the rearmost edge of a high pressure port, a second next successively advancing piston element is, by the continued rotation of the rotor element, already disposed between such high pressure port edge and the corresponding low pressure port, to preclude undesired back flow from the high pressure port to the low pressure port.

With such an arrangement the advance of the next successively advancing pistonelement in the manner described eflectively precludes undesired direct flow of fiuid around the annular chamber from the high pressure port to the low pressure port, i.e. precludes back flow in the case of a pump, and in the case of a motor precludes flow of the fluid in a direction which is ineffective in power driving the rotor element of the motor.

From the foregoing it will be understood that essentially the present invention embodies inter alia the following important four features:

(a) The number of piston elements on the rotor element is greater than the total number of inlet ports and greater than the total number of outlet ports, so as, as above described, to avoid the disadvantages of the arrangement of my prior proposal, including its experimental prototype. e

(b) Each disc-like rotary valve element is for a given direction of rotation of the rotor element, arranged to rotate in one direction only as opposed to each rotary valve element being in the form of a plurality of apertured disc-like members arranged to rotate in opposite directions with a piston element passing therethrough when an aperture of one disc-like member is momentarily in register with an aperture of another oppositely rotating disc-like member.

In the case where the rotary valve element comprises two oppositely rotating apertured disc-like members, by

reason of the necessity to form each member to an appreciable thickness in order to withstand the fluid pressure obtaining within the annular chamber, it is necessary, since the disc-like valve members are rotating in timed relation with the rotor element, to make the apertures of the disc-like members of an appreciably greater width in the direction of rotation than the width in such direction of each piston element. Otherwise it would be quite impossible for the two apertures of a pair of oppositely rotating disc-like members of the necessary thickness above indicated to be sufliciently in register with one another as to permit of the passage therethrough of a piston element. Thus in practice, the aforementioned difference in width between each disc-like member aperture and the piston element becomes so great that a back flow of high pressure fluid will occur during the passage of the piston element through the two apertures of the oppositely rotating disc-like members as substantially to nullify the advantage of providing the rotor elements with a number of piston elements greater than the total of inlet ports and greater than the number of outlet ports in accordance with feature (a) above specified.

There is accordingly an important inventive combination between features (a) and (b) of the present invention.

(c) The third important feature of the present invention is that the plane of rotation of each disc-like rotary valve element is transverse as opposed to being parallel to the direction of passage of the piston element through the aperture in the valve element.

If the plane of rotation aforementioned were parallel to such direction of passage of the piston element, it would in practice be necessary to provide such a large clearance between the edges of each piston element and the edges of the aperture to allow for the relative directions of rotation of the valve element and piston element without these two elements fouling one another, that again at this instant in the operation of the pump or motor the back flow of the high pressure fluid through the clearance space so required would be so great as to nullify the effect of providing feature (a) above mentioned of the present invention. There is thus an important inventive combination between the three features (a), (b) and (c) above mentioned.

Thus, as applied both to a rotary pump and rotary motor, the present invention possesses the important advantage over the arrangement of my prior proposal aforementioned that the output of the pump or motor is maintained during each complete rotation of the rotor element apart from a momentary reduction in output as each piston element passes through the or one of the apertures in the valve element which is rotating in timed relation with the rotor element.

Furthermore, in the case of a rotary pump, there is no return flow through the annular chamber, of fluid which has already been delivered past the outlet port.

Most importantly in the case of a rotary pump for pumping liquids, e.g. water, there is no water hammer as occurred in the experimental operation of the prototype according to my prior proposal aforementioned, the elimination of such water hammer with the present invention being consequential on the avoidance of a sudden reduction in delivery pressure, as occurred, for the reason explained, with the prior proposal.

((1) The fourth of the foregoing referred to four features is that the outlet port is disposed immediately adjacent to the position of intersection of the corresponding rotary valve element with the annular chamber.

The effect of this in the case of a pump is that each pump piston as it advances past the outlet or high pressure port of the pump immediately passes into the aper- 4 ture of the adjacent valve element, and the result of this is that there is no pocket in the annular chamber between the outlet or high pressure port of the pump in which the fluid, e.g. water can be undesirably compressed without access to any outlet as a piston element advances past the outlet or high pressure port up to the not yet open valve element.

In the alternative case in which the invention comprises a rotary motor, by disposing the high pressure port of the motor immediately adjacent to the position of intersection of the corresponding valve element, as a piston element advances the position of intersection of the valve element with the annular chamber, it at once commences to uncover the high pressure or inlet port of the motor. Thus with the present invention as applied to a rotary motor, there is no dead pocket in which no useful work of any kind is done in the annular chamber between the aforementioned intersection of the valve element and the high pressure or inlet port of the motor, and in which dead pocket the high pressure fluid supplied from the inlet port would act undesirably to resist the advancement of the piston therethrough.

In order that the invention may be more clearly understood, reference is now made to the accompanying drawings wherein:

FIGURE 1 is a sectional side elevation in diagrammatic form of a rotary pump as conceived by me in my prior proposal aforementioned.

FIGURE 2 is a cross-sectional view of a rotary pump specifically designed for pumping water or other liquids and embodying the present invention.

FIGURE 3 is a cross-sectional view of the same pump on the line 3-3 of FIGURE 2.

FIGURE 4 is a sectional view on the line 4-4 of FIGURE 3.

FIGURE 5 is a side elevation of the Valve element of the pump depicted in FIGURES 2 to 4.

Referring firstly to FIGURE 1 of the drawings, the rotary pump there illustrated in accordance with my prior proposal aforementioned, comprises a casing 10 having an annular chamber 11, the casing also containing a rotor element 12 provided with a single piston element 13, which traverses the annular chamber 11. The pump is further provided with a rotary valve element 14, which intersects the annular chamber '11, and which through means, not shown, is arranged to rotate in timed relation with the rotation of the rotor element 12; the valve element 14 being provided with an aperture, not shown, which permits of the passage therethrough of the piston element 13.

The pump is provided with a low pressure or inlet port 15, and a high pressure or outlet port 16 disposed on opposite sides of the position of intersection of the valve element 14 with the annular chamber '11, which ports lead respectively into and out of the annular chamber with the outlet port 16 extending tangentially in relation to the annular chamber 11.

Thus the piston element 13 when advanced by the power driven rotor element 12 through the aperture in the valve element 14 and past the inlet port 15 in a direction away from the adjacent valve element, serves positively to force the liquid around the annular chamber in the direction of rotation of the rotor element depicted by the arrow in FIGURE 1 to the outlet port 16.

In FIGURE 1 the single piston element 13 provided is shown in a position in which its has advanced just past that edge 16a of the outlet port 16, which is rearmost in the direction of rotation of the piston element with the latter still on the high pressure or outlet side of the valve element 14 at its intersection with the annular chamber 11.

Thus between the circum-ferentially rotating piston ele ment 13 and the rearward edge 16a of the outlet port 16 there is now a space S through which the liquid which has been forced under pressure to the outlet port can flow freely back around the annular chamber to the inlet port 15, with the resultant serious disadvantages of this prior proposal aforementioned.

Referring now to FIGURES 2 to 5 illustrating a rotary pump for pumping water or other liquid, in accordance with the present invention, and examining firstly FIG- URE 2, it will be seen that the pump there depicted is broadly similar to the pump diagrammatically illustrated in FIGURE 1, with the very important exception that in accordance with the present invention instead of the rotor element 12 being provided with a single piston element 13, it is provided with a plurality of piston elements, namely two piston elements 13a, 13b, spaced circumferentially around the rotor element 12 at diametrically opposite sides thereof.

The spacing of these two piston elements 13a, 13b, is such that when as shown in FIGURE 2, one of these piston elements 13a commences on movement into the dotted position 13ai to uncover the aforementioned rearmost edge 16a of the high pressure or outlet port, the other piston element 13b, i.e. the next successive advancing piston element is, by the continued rotation of the rotor element 12, disposed in the dotted position 1312:, which as in full line position 13b is between such high pressure port 16 and the corresponding, i.e. single low pressure or inlet port 15 provided in this particular pump.

Thus, despite the existence of the aforementioned space S, between piston element 13a in position 13m, and outlet port edge 16a, the back flow of high pressure liquid around the annular chamber 11 in a direction opposite to the direction of rotor rotation to the inlet port 15 is now positively prevented by the presence in such direction of flow around annular chamber 11 of this second piston element 13b between the outlet port 16 and the inlet port 15.

As a result, the above mentioned advantages of the present invention are obtained.

As will readily be seen from FIGURE 2, the inlet and outlet ports 15, 16 which are disposed on opposite sides of the valve element 14 are respectively disposed itnmediately adjacent the position of intersection of the valve element 14, with the annular chamber 11, for the purpose in the case of a pump which has already been fully explained. 4

The casing 10, as shown in FIGURE 3, is provided with bearings 17 which support a rotor element driving shaft 18, on one end of which is mounted the rotor element 12, and this rotor element comprises a central hub portion 12a, which through a spoked portion 12b is connected to a rim portion 120 carrying the two diametrically opposed piston elements 13a and 13b, as shown in FIGURE 3, and which work within the annular chamber 11, which chamber is conveniently of square form in cross section.

The spaces between the spokes of the spoke portion 12b of the rotor element provide for the passage therethrough of the water or other liquid from an inlet passage 19, provided by the interior of part of the casing 10, this inlet passage communicating through the aforementioned space between the rotor element spokes with an annular inlet chamber 20, which, as shown in FIG- URE 2, leads into the inlet port 15.

The rotor driving shaft 18 has mounted thereon a skew gear wheel 21, which, as shown in FIGURE 4, meshes directly with a second skew gear wheel 22 mounted on a valve shaft 23 extending at right angles to rotor shaft 18, and carrying at one end the valve element 14 as shown in FIGURES 2, 4 and 5. The valve element 14 is in the form of a single disc-like member of circular configuration peripherally and insofar as its associated shaft 23 is driven through the gear wheels 21, 22 from the rotor shaft 18 it will be understood that this single disc-like member constituting the valve element 14 is rotated in one direction only and in timed relation with the rotation of the rotor element 12.

The valve shaft 23 is supported from part of the casing 10 by suitable bearings 24, 25, the latter being disposed adjacent the end of the shaft 23, which is furthest from the valve element 14.

The valve element 14 is in the arrangement illustrated driven through the gear 21, 22 at an angular velocity the same as that of the rotor element 12, and as the latter is provided with two piston elements, the disc-like valve element 14 is provided at diametrically opposed positions, as shown in FIGURE 5, with two apertures 26a, 26b, which are presented in turn to the position of intersection 27 of the valve element with the annular chamber 11 at the instant that each of the pistion elements advances past this position of intersection.

As will be readily apparent from FIGURES 2 and 4, the plane of rotation of the valve element 14 is inclined to, i.e. transverse to, the direction of passage of the piston element through the apertures in the valve element.

Referring to FIGURE 2, it will be noted that the radius line R between the axis of rotation of the rotor element 12 and each piston element at its intersection position 27 is inclined to the plane of rotation of the disc-like valve element 14.

Such inclination of the plane of rotation of the valve element 14 to the radius line R, permits, as shown in FIGURE 4, of the valve element 14 being mounted on one end of its associated shaft 23 at a position clear of the rotor element shaft 18, and the latter and the valve element shaft 23 extending at right angles to one another, and being thus drivingly connected in a particularly simple manner, namely by the two gears 21, 22. It is important that the simplest possible drive should be provided between the rotor element shaft 18 and the valve element shaft 23, so as to minimize back lash in the drive and thus ensure that each aperture 26a, 26b in the valve element 14 is presented in precise timed relation with the advancement thereof of each piston element 13a, 13b, whereby the configuration of each valve element aperture can be made to conform as closely as possible to the peripheral shape of each piston element, and leakage of fluid during the momentary passage of each piston element through the valve element minimised. Having regard to the foregoing, and the fact that the valve element 14 is rotating continuously during the passage of each piston element through the apertures 26a, 26b, it is necessary for each piston element to be of helicoidal configuration as shown in FIGURE 2, and for the walls of each aperture in the valve element to be shaped to correspond.

The outer periphery of the disc-like valve element 14 works within an annular channel 28 which communicates with the annular inlet or low pressure chamber 20, through a slot-like opening 28a, see FIGURE 2. The width of both the slot-like opening 28a as well as the annular channel 28, are in each case greater than the thickness of the disc-like valve element 14, While the peripheral diameter of the latter is less than the internal diameter of the annular chamber 28. In fact the internal dimensions of the valve housing relative to the diameter and thickness of the valve member 14, are such that a substantial clearance is provided between all surfaces of the valve member and the housing as indicated at a and b. However, the slot 28a at the area 0 through which the valve element 14 projects into the annular chamber 11 is dimensioned so as to provide minimum working clearance relative to the valve element 14 to reduce the amount of fluid which passes from the annular chamber 11 through the slot 28a into the valve housing 13.

Thus a space for liquid is provided on each face of the peripheral portion of the valve element 14 as well as around the outer periphery thereof into which liquid can freely pass through the slot 28a from the inlet chamber 20 and thus apply an equal pressure on each side of the outer portion of the disc-like valve element 14, whereby the distortion of the outer periphery of this disc-like valve element under the effect of the liquid pressure is minimised.

In other words the substantial clearance between the valve element 14 and the walls of the slot 28a at the areas d and e allows water to pass freely from the inlet port 15 into the valve housing and applies equal pressure to substantially all surfaces of the valve element. The only portion of the valve element 14 which is subject to a liquid pressure different from that obtaining in the inlet chamber 20, is where the valve element extends across the annular chamber 11. Thus there is no distortion of the remainder of the valve member due to unbalanced pressure acting thereon and resultantly no frictional contact between the valve member and the valve housing. Thus the disc-like valve element 14 may be made only of sufiicient thickness to enable it to function as a valve element and it is not necessary specially to increase its thickness for the purpose of making the element sufficiently rigid to resist distortion arising from unbalanced fluid pressure at the periphery of the valve element. Accordingly by reason of this relatively small thickness of the valve element 14 its presence within the annular chamber 11 reduces the volume of this chamber and thus the swept volume of each piston element to the minimum extent as is indeed desirable.

The casing is formed with a slot 28b to accommodate the valve element 14 where this intersects the annular chamber 11 and this slot is made of a width which is greater than the thickness of the valve element 14 by an amount sufficient only to provide minimum Working clearance at this position so as thus to minimise leakage of liquid from the annular chamber 11 adjacent the high pressure or outlet port 16.

At the intersection position 27 between the valve element 14 and the annular chamber 11, the one face of the valve element directed to the adjacent outlet port 16, is subjected to the full pressure of the outlet port 16, which exerts an end thrust on the valve spindle 23 in a direction towards the bearing 25 and this bearing may ac cordingly be formed as a thrust bearing.

The outlet port 16 leads into a flanged outlet passage 31] adapted to be connected to a suitable liquid delivery pipe.

The casing 10, is so formed as to provide a sub-casing 31 for oil to provide for lubrication of the gears 21, 22.

The rotor element driving shaft 18 is adapted to be power driven from any suitable power source, and the particular pump illustrated has been specially designed for mounting on an agricultural or other tractor, with the shaft 18 adapted to be connected through a suitable universally jointed shaft to the power take off shaft of the tractor.

Suitable seals 32 are provided between the two piston elements 13a13b and the adjacent rotor element 12, which rotor element is disposed in that part of the casing 10 which is in communication with the inlet port and is thus at low pressure, and for this purpose each piston element is of substantially T-configuration with the stem 33 which is carried on the rim portion 12a of the rotor element extending between the two concentric sealing rings constituting the aforementioned seal 32, which sealing rings are in sealing engagement with the adjacent face 12d of the rim portion 120. The arrangement is such that leakage from the high pressure side of each piston element to the inlet side of the pump past the rim portion of the rotor element 12 is effectively prevented.

With the present invention, it will be understood that the valve element 14 serves to prevent any appreciable flow of liquid from the high pressure port 16 on one side thereof at the intersection position 27, to the low pressure port on the opposite side thereof, such liquid flow only occurring momentarily when each of the apertures 26a, 26b in the valve element 14 are presented to the intersection position 27 for the passage through the valve element of each of the piston elements 13a, 13b.

In addition to possessing the various advantages above described, a rotary pump in accordance with the present invention is well adapted for pumping solid matter in suspension. This is because the solid matter is not required to pass any valve during its passage through the pump, it is only the piston elements themselves which are required to pass through apertures in the valve element 14. Accordingly, the operation of the valve element and thus of the pump is not likely to be impaired by any scouring action of the solid matter in suspension of the liquid, even when the solid matter is of an abrasive character.

A rotary pump in accordance with this invention specifically designed for the pumping of water, which is one of its principal applications, possesses a particularly high efliciency which calculations show to be of the order of a figure which is considerably higher than the efficiency figure of an ordinary centrifugal pump of modern design, the efiiciency of which is commonly about 55%.

Also calculations show that a rotary pump in accordance with the present invention specifically designed for pumping water has particularly good delivery characteristics, even where the overall size of the pump may be quite small.

For example, in the case of the particular pump illustrated in FIGURES 2 to 5 of the accompanying drawings, in which the rotor element has an overall diameter of approximately 11 inches working at 540 rpm, calculations show that the output characteristics or duty of the pump are 109 gallons of water per minute with an output pressure of pounds per square inch.

A rotary pump or a rotary motor in accordance with this invention is capable without substantial modification thereof of operating as a rotary motor or a rotary pump respectively.

For example in the case of the rotary pump, particularly described herein with reference to FIGURES 2 to 5 of the accompanying drawings, the pump may be arranged to operate as a motor by utilising the pump outlet port 16 as the high pressure inlet port of the motor, and utilising the pump inlet port 15 as the low pressure outlet port of the motor, the rotor element of which would then run in a direction the reverse of that above described.

For this purpose, it would then be desirable for the disc-like valve element 14 to be arranged symmetrically in relation to the direction of fluid flow, i.e. for the disclike valve element where it intersects with the annular chamber to have its plane lying on a diameter of the rotor element, so that the valve element is then equally effective for either direction of rotation of the rotor element.

What I claim then is:

1. A rotary pump or motor comprising a casing having an annular chamber, the casing containing a rotor'element provided with a plurality of piston elements traversing the annular chamber, and spaced circumferentially therearound, one or. more rotary valve elements of disc-like form, intersecting the annular chamber, means for rotating each of said valve elements in timed relation with the rotation of the rotor element, each valve element being arranged to rotate in one direction only for a given direction of rotation of the rotor element, each valve element being apertured to permit of the passage therethrough of each piston element, means supporting each disc-like valve element for rotation in a plane acutely inclined to the direction of advancement of each piston element through the valve element, an inlet and outlet .port to the annular chamber positioned respectively on opposite sides of the position of intersection of each rotary valve element with the annular chamber, each outlet port being disposed immediately adjacent to the position of intersection of the corresponding rotary valve element with the annular chamber, the number of piston elements being greater than the total number of inlet ports and greater than the total number of outlet ports, and the arrangement being such that at the instant that a piston element commences to uncover the rearmost edge of a high pressure port, a second next successively advancing piston element is, by the continued rotation of the rotor element, already disposed between such high pressure port edge and the corresponding low pressure port, to preclude undesired back flow from the high pressure port to the low pressure port.

2. A rotary pump or motor according to claim 1, wherein a single disc-like valve element is provided together with one low pressure port and one high pressure port arranged on opposite sides of the position of intersection of the valve element with the annular chamber, and the rotor element is provided with two piston elements arranged on diametrically opposite sides of the rotor element.

3. A rotary pump comprising a casing having an annular chamber, the casing containing also a rotor element provided with a plurality of plate-like piston elements spaced circumferentially therearound with the plane of each plate-like'piston element being substantially radial in relation to the axis of rotation of the rotor element with each piston element successively traversing the annular chamber, a rotary valve element in the form of a single fiat disc intersecting the annular chamber means for rotating said valve element in one direction in timed relation with the rotation of the rotary element, said single disc-like valve element being so apertured as to permit, by its rotation, of the passage therethrough of the successively advancing plurality of piston elements of the rotor element, means supporting said flat disc-like valve element for rotation in a plane acutely inclined to the direction of advancement of each piston element therethrough, a low pressure inlet port and a high pressure outlet port to the annular chamber positioned respectively on opposite sides of and immediately adjacent to the position of intersection of the rotary valve element with the annular chamber, said low pressure and high pressure ports being disposed respectively at the circumferential sides of the annular chamber which are respectively nearer to and further from the axis of rotation of the rotor element, said outlet port communicating with a high pressure outlet passage extending in a direction away from the rotor element axis substantially parallel to the plane of the flat disc-like valve element.

4. A rotary pump or motor according to claim 1, characterized in that the valve element is mounted on one end of a rotatable shaft extending at right angles to a shaft on which the rotor element is mounted, with the two shafts being connected together by gearing comprising two gear wheels mounted one on eachrof the two shafts in direct meshing engagement with one another, with the plane of rotation of the valve element inclined to a radius line extending from the axis of rotation of the rotor element to the position of intersection of the valve element with the annular chamber.

5. A rotary pump comprising a casing having an annular chamber, a piston element rotatably supported to traverse said annular chamber, a valve element rotatably supported in the casing to transversely intersect the annular chamber and having an aperture to permit passage therethrough of the piston element, said piston and valve elements being interconnected to rotate in timed relation to align said aperture with the annular chamber for the passage of the piston element therethrough, and inlet and outlet ports communicating with the annular chamber adjacent to and on opposite sides of the valve element, the valve element and the portion of the casing housing the valve element being so constructed and relatively arranged that fluid entering said portion of the casing has free access to each face of the valve element.

6. A rotary pump as claimed in claim 5, wherein the valve element is a discal member formed with a peripheral notch to permit the passage of the piston element therethrough, and the valve element is housed in a portion of the casing in communication with the inlet port r 10 and having a substantial clearance relative to the valve element so that a uniform fluid pressure will exist throughout said portion of the casing.

7. A rotary pump as claimed in claim 5, wherein the casing forms an inlet chamber disposed radially inwardly with respect to the annular chamber and communicating therewith through the inlet port, and a valve housing normal to and communicating with the annular chamber and the inlet chamber through an elongated opening, the valve element being a discal member journalled in the valve housing and projecting through the elongated opening to intersect the annular chamber the width of the elongated opening being reduced where the opening communicates with the annular chamber to provide a minimum running clearance relative to the valve disc.

8. A rotary pump comprising a casing having an annular chamber, two or more piston elements rotatably supported to traverse said angular chamber in unison in a fixed angular relation, a valve element rotatably supported in the casing to transversely intersect the annular chamber, apertures in said valve element equal in number to the number of piston elements to permit passage therethrough of the respective piston elements, said piston elements and valve elements being interconnected to rotate in timed relation to successively align the apertures with the annular passage for the passage of the respective piston elements therethrough, and inlet and outlet ports communicating with the annular chamber adjacent to and on opposite sides of the valve element, the valve element and the portion of the casing housing the valve element being so constructed and relatively arranged that fluid entering said portion of the casing has free access to each face of the valve element.

9. A rotary pump as claimed in claim 8, wherein the portion of each piston disposed in the annular chamber is shaped in the circumferential direction of the chamber in the form of a helix, and each aperture in the valve element is shaped to mate with the helix form of the piston so that they mesh in the manner of mating gear teeth as the piston passes through the aperture.

10. A rotary pump as claimed in claim 8, wherein the casing forms an inlet chamber disposed radially inwardly with respect to the annular chamber and communicating therewith through the inlet port, and a valve housing normal to and communicating with the annular chamber and the inlet chamber through an elongated opening, the valve element being a discal member journalled in the valve housing and projecting through the elongated opening to intersect the annular chamber, the width of the elongated opening being reduced where the opening communicates with the annular chamber to provide a minimum running clearance relative to the valve disc.

11. A rotary pump comprising a casing having an annular chamber, two or more piston elements rotatably supported to traverse said chamber in unison in a fixed angular relation, a pair of discal valve elements rotatably supported in said casing to transversely intersect the annular chamber at respective diametrically opposite positions, at least one aperture in each valve element shaped to permit the passage therethrough of the latter, said piston elements and valve elements being interconnected to rotate in timed relation to align the/or an aperture with the annular chamber for the successive passage therethrough of the respective piston elements, and inletand outlet ports communicating with the annular chamber adjacent to and on opposite sides of each valve element, the valve elements and the portions of the casing housing said valve elements being so constructed and relatively arranged that fluid entering said portion of the casing has free access to all faces of each valve element.

12. A rotary pump as claimed in claim 11, wherein each valve element is a discal member formed with a number of peripheral notches equal to the number of piston elements to permit the passage of the piston element therethrough, and each valve element is housed in respective portions of the casing in communication with the inlet port and having a substantial clearance relative to the valve element so that a uniform fluid pressure will exist throughout said portion of the casing.

13. A rotary pump as claimed in claim 12, wherein the portion of each piston disposed in the annular chamber is shaped in the circumferential direction of the chamber in the form of a helix, and each aperture in the valve element is shaped to mate with the helix form of the piston so that they mesh in the manner of mating gear teeth as the piston passes through the aperture.

References Cited UNITED STATES PATENTS 12 6/1930 Wheat et al. 103125 11/1946 Biermann 230150 3/1950 Biermann 230-150 1/1957 Strader 12313 12/1961 Renshaw 123--13 FOREIGN PATENTS 7/1951 Australia. 6/1914 France. 9/ 1945 France.

DONLEY I. STOCKING, Primary Examiner.

WILBUR J. GOODLIN, Examiner. 

1. A ROTARY PUMP OR MOTOR COMPRISING A CASING HAVING AN ANNULAR CHAMBER, THE CASING CONTAINING A ROTOR ELEMENT PROVIDED WITH A PLURALITY OF PISTON ELEMENTS TRAVERSING THE ANNULAR CHAMBER, AND SPACED CIRCUMFERENTIALLY THEREAROUND, ONE OR MORE ROTARY VALVE ELEMENTS OF DISC-LIKE FORM, INTERSECTING THE ANNULAR CHAMBER, MEANS FOR ROTATING EACH OF SAID VALVE ELEMENTS IN TIMED RELATION WITH THE ROTATION OF THE ROTOR ELEMENT, EACH VALVE ELEMENT BEING ARRANGED TO ROTATE IN ONE DIRECTION ONLY FOR A GIVEN DIRECTION OF ROTATION OF THE ROTOR ELEMENT, EACH VALVE ELEMENT, BEING APERTURED TO PERMIT OF THE PASSAGE THERETHROUGH OF EACH PISTON ELEMENT, MEANS SUPPORTING EACH DISC-LIKE VALVE ELEMENT FOR ROTATION IN A PLANE ACUTELY INCLINED TO THE DIRECTION OF ADVANCEMENT OF EACH PISTON ELEMENT THROUGH THE VALVE ELEMENT, AN INLET AND OUTLET PORT TO THE ANNULAR CHAMBER POSITIONED RESPECTIVELY ON OPPOSITE SIDES OF THE POSITION OF INTERSECTION OF EACH ROTARY VALVE ELEMENT WITH THE ANNULAR CHAMBER, EACH OUTLET PORT BEING DISPOSED IMMEDIATELY ADJACENT TO THE POSITION OF INTERSECTION OF THE CORRESPONDING ROTARY VALVE ELEMENT WITH THE ANNULAR CHAMBER, THE NUMBER OF PISTON ELEMENTS BEING GREATER THAN THE TOTAL NUMBER OF INLET PORTS AND GREATER THAN THE TOTAL NUMBER OF OUTLET PORTS, AND THE ARRANGEMENT BEING SUCH THAT AT THE INSTANT THAT A PISTON ELEMENT COMMENCES TO UNCOVER THE REARMOST EDGE OF A HIGH PRESSURE PORT, A SECOND NEXT SUCCESSIVELY ADVANCING PISTON ELEMENT IS, BY THE CONTINUED ROTATION OF THE ROTOR ELEMENT, ALREADY DISPOSED BETWEEN SUCH HIGH PRESSURE PORT EDGE AND THE CORRESPONDING LOW PRESSURE PORT, TO PRECLUDE UNDESIRED BACK FLOW FROM THE HIGH PRESSURE PORT TO THE LOW PRESSURE PORT. 